Donald Dankert testified on Thursday at his murder trial. He is accused of killing his son, who was 4, in 2003.

TAMPA — Donald Dankert didn't tell his girlfriend about the blood he found in his baby's diaper before he left for the hospital. He didn't write about it in his statement to detectives. He didn't alert the doctors trying to save the infant's life.

That blood, prosecutors said, passed through the body of 4-month-old Dylan Dankert after he endured more than one intentional, forceful blow to the abdomen.

On the witness stand Thursday at his own first-degree murder trial, Dankert, 27, maintained his innocence. He told jurors the same story he had told others.

On the last morning he held his son, Dec. 19, 2003, he was getting ready to set the boy in his crib when a dog barked and startled him.

"I dropped him," he testified. Dankert's lips quivered. His eyes watered. He said he jerked his knee up as the baby fell.

"And what happened to the baby?" his attorney, Theda James, asked.

"He got hit in the stomach and he rolled," Dankert said. "I'm pretty sure I caught him before he hit the floor. But it happened in the blink of an eye."

Dankert's story didn't add up, a medical examiner testified. Not to the list of injuries:

Lacerated intestine. Bruised head, torso and extremities, with some marks in the shape of fingertips. Some injuries were older than others.

Dankert said he saw none of them. The baby's mother, Tanya Gruce, 35, who changed his diaper that morning, said she didn't see any, either.

She is charged with aggravated manslaughter because prosecutors say she didn't immediately seek medical attention for the child. She is being tried separately. She was at work at the time of the incident Dankert described, but the examiner said the fatal blow came hours earlier.

"That story could essentially be ruled out," Dr. Daniel Spitz said. "It was more of an aggressive impact — punch, kick, elbow, knee. Something along those lines."

Dankert said the baby cried after the fall, but stopped after being comforted. He left the baby in his crib. Minutes later, Dankert returned to the nursery to find something wrong with the baby's eyes.

He picked up the infant and felt a heavy diaper, he said. He realized it was full of blood. Detectives found bloodstains on two diapers, a rug and a changing table.

Dankert rushed to the hospital at noon, clutching an infant with no pulse. He told doctors everything he told the jury, minus the part about the blood.

Prosecutor Jalal Harb asked him why he left out such an important detail.

"Now, you knew as a father," Harb said, "that it's important when you go to the doctor that you tell the doctor everything that's wrong with the child."

Dankert responded, "This wasn't a normal doctor visit."

Jurors are expected to begin deliberations today.

Alexandra Zayas can be reached at azayas@sptimes.com or (813) 226-3354.